R devel - May 2006 - expression objects

if 'e' is a vector of mode 'expression', will the following
always
return TRUE:

identical(e, parse(text = as.character(e)))  ?

 > (e <- expression(x, y, z, 200*f%/%d, sin(e)))
expression(x, y, z, 200 * f%/%d, sin(e))
 > identical(e, parse(text = as.character(e)))
[1] TRUE

i have been relying on this fact in some of my code, and would be  
appreciative of any counterexamples.

franklin parlamis

Try this:

   e <- as.expression("A")
   identical(parse(text = as.character(e)), e) # FALSE


On 5/2/06, Parlamis Franklin <fparlamis at mac.com>
wrote:
> if 'e' is a vector of mode 'expression', will the following
always
> return TRUE:
>
> identical(e, parse(text = as.character(e)))  ?
>
>  > (e <- expression(x, y, z, 200*f%/%d, sin(e)))
> expression(x, y, z, 200 * f%/%d, sin(e))
>  > identical(e, parse(text = as.character(e)))
> [1] TRUE
>
> i have been relying on this fact in some of my code, and would be
> appreciative of any counterexamples.
>
> franklin parlamis
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>